Indian Trail Caverns, first opened in 1927, is one of many caves on the dolomite ridge traversed by State Route 568 in Wyandot and Hancock counties. Sheriden Cave, a karst sinkhole associated with the caverns, was discovered in 1989 and has preserved a remarkable record of Ice Age animal and human activity in its sediments. Excavations have uncovered remains of many extinct Late Pleistocene Epoch animals, including giant beaver, stag moose, flat-headed and long-nosed peccary, and short-faced bear, among many others, sealed in the cave by glacial deposits more than ten thousand years ago. Paleo-Indian tools, including projectile points and scrapers, provide evidence of the earliest-known human activity in this region.
